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While gang injunctions are novel in New York, jurisdictions in California and other states have used them for years.

But unlike New York, the California criminal code defines criminal gang activity in its statute - giving that state a critical legal underpinning for the law enforcement strategy.

Officials in Suffolk County say the limited scope of their proposal - which details a limited area, a small number of gang members and a list of specific proscribed behaviors - will help it pass legal muster.

However, such an initiative has never been undertaken on Long Island, and at least one observer says he's not convinced the California experience can be replicated here.

"Courts may not be happy about the DA or police importing effectively a scheme based upon another state's statutes when we don't have a statute," said Jim Cohen, a professor at Fordham Law School and a practicing criminal attorney.

Cohen said that the county could rely on public nuisance statutes, but that may not be enough to hold up in court when the county seeks an injunction.

Officials in San Diego County, Calif., credit the 19 gang injunctions they've instituted since 1997 with reducing crime in gang turf there.

Shawnalyse Ochoa, the deputy district attorney in San Diego who works on gang injunctions, said the county spends a year crafting each injunction. Each gang member is named, along with their gang history.

Affected gang members are not allowed to congregate with other members in the gang's territory - the "safe zone" that the injunction establishes.

While civil liberties defenders have opposed the gang injunctions, in California, the measures have survived legal opposition.

A 2002 study by a University of Chicago professor found that 14 injunctions reduced the amount of reported violent crimes in different areas in Los Angeles by 5 percent to 10 percent.

Other jurisdictions have also reported success with the measures, including the city of San Francisco, Calif., which found a "cooling off" effect of gang activity after they instituted injunctions against five gangs.The city of St. Paul, Minn., used temporary gang injunctions in 2009 to reduce violence in the days around two popular street festivals.